Method of ventilating tunnels.



A. C. DENN|S. METHOD OF VENTILATING TUNNELS.

APPLICATION FILED OCT. 18, !9l5-v Patenfpd Dec. 5, 1916.

INVENTOR A ltorneys mr Nnums PETER! cownomummwuumc mu. 0 c

rrnn saa'rs raanr anion ARTHUR CRISFIELI) DENNIS, OF GLACIER, BRITISH COLUMBIA, CANADA.

METHOD OF VENTILATING TUNNELS.

Specification of Letters Patent.

Patented Dec. 5, 1916.

Application filed October 18, 1915. Serial No. 56,586.

. method of ventilating train tunnels and the object of the invention is to provide a method which will effectively prevent the accumulation of smoke in tunnels during the passage of trains, such being accomplished by the use of high pressure air and it consists essentially in the arrangement, construction and operation of parts hereinafter described and later pointed out in the appended claims.

Figure 1 represents a longitudinal sectional view through a tunnel equipped with my invention. Fig. 2 represents an end elevation of the tunnel. Fig. 3 represents an enlarged detailed vertical sectional view through one of the ventilating pipe rings.

In the drawing like characters of reference indicate corresponding parts in each figure.

In carrying out the presentinvention I utilize, as storage compartments for the compressed air, my pioneer heading, such being a special heading provided when tunneling and forming the basis of a co-pending application. In so far as this invention is concerned, this pioneer heading is considered supplied, having been excavated during the tunnel work, and in this application I use the pioneer heading to store the compressed air, such heading being divided into a series of compartments all or any of which can be drawn on as a source of supply when desired.

Referring now to the drawing, 1 repre sents the main train tunnel which it is desired to ventilate, this being equipped in the present instance with double tracks 2 and 3, as shown, for the passage of the train.

Adjacent the main tunnel and running parallel therewith is located the pioneer tunnel 1 which is, obviously, considerably smaller in cross section than the main tunnel. The pioneer tunnel is divided by a series of cement or other such like bulkheads 5 into a series of compartments 6, 7 and 8 and each of these compartments can be approached through cross-cuts or passages 9 from the main tunnel, the passages being blocked by suitable barriers 10, fitted with manholes 10.

In supplying the high pressure air method to the main tunnel for ventilating purposes, I provide, at one of the entrance ends of the tunnel, a series of hollow or tubular pipe rings 11, 12 and 13, these rings passing around the wall of the tunnel and across the bottom thereof and being provided with contracted, inclined, inwardly directed air nozzles 1 1. The lower portions of these rings pass under the tracks so that they are entirely out of the way.

At the side of the tunnel, at the entrance end, I locate an operating tower 15 and from the operating tower I pass an air pipe 16 into the pioneer tunnel, this air pipe passing through to the bulkheads and opening to the last compartment, or that numbered 8. Vithin the air compartment 7 this pipe is supplied with a valve 17 and the valve can only be approached through the crossvcut leading to the compartment 7 and by way of the manholes supplied.

Branch air pipes 18 and 19 connect the main pipe through the bulkheads with the compartments 6 and 7 respectively and these branch pipes are each supplied with controlling valves 20 and 21, the valve 20 being approached through the manholes of the cross-cut 7 leading to the compartment (5.

22 represents a high pressure air compressor and 23 represents a supply pipe leading from the compressor to the pipe 16. This pipe is supplied with a valve 24:.

. 25, 26 and 27 represent feed pipes which connect within the tower with the pipe 16 and lead from the tower to the rings 11, 12 and 13 respectively. Within the tower each of the feed pipes is supplied with a throttle valve 28.

In carrying out my method of ventilating, the compartments 6, 7 and 8 are first filled with compressed air at a high pressure, this air being passed into the respective compartments by opening the valves 24, 17, 18 and 19 and closing the valves 28. After the required pressure is gotten in the compartments the valve 21 is closed as are also the valves 19 and 20, the valve 17 remaining open. The compartments 6 and 7 then become auxiliary storage chambers while the compartment 8 is the working storage chamber.

WVith the valves set as just described, the operator within the tower can control the passage of the compressed air to the pipes 25, 26 and 27 by manipulating the respective valves 28 and in so doing control the escape of the air through the nozzles 14: and rings 11, 12 and 13.

In connection with the compartments, it might be well to explain that while these look rather short in the drawing, they are in reality in tunnel work, each possibly upward of two thousand feet long so that each one of them, when once charged, so to speak, to the desired air pressure, forms a particularly large air reservoir which will maintain an air supply for the nozzles for a considerable period.

From the above it is obvious that the air compressor does not need to be working all the time but only after the air in all the compartments has become about exhausted.

As an actual example, the air in the compartments would. be brought to a pressure ofpossibly one hundred to one hundred and twenty-five pounds gage and would have a discharge velocity through the nozzles ot about seven miles per minute. Acco1 '-;li11gly, it is possible with this method to get the desired velocity of free air through long tunnels unereas, under a low pressure blower system, as now generally used, it is not feasible and further, the cost of installation and upkeep of this latter system is very high whereas in mine it is exceptionally low.

The way in which my method operates is that sufiicient compressed air is discharged around the edges of the tunnel in the directien in which the train is moving, to induce a draft through the tunnel of free air, traveling at a slightly greater velocity and in the same direction as the train and thereby blowing the smoke and gases ahead of the locomotive and leaving the train traveling in good fresh air.

While I have given in the example above definite figures for the pressure and velocity I might explain that it is only necessary that the pressure and arrangement be such that the nozzles discharge into the tunnel compressed air of sufiicient volume and pressure to overcome the resistance of the volume of free air in the tunnel moving at the required velocity.

The nozzles are installed so that they are spaced and pointed to discharge the compressed air on the area of the entire tunnel section and in so doing induce free air to enter the main tunnel by reason of the partial vacuum formed behind the pipe rings and also impart its velocity and pressure to the air ahead of the rings. The pressure in the rings is regulated by the operator through the throttle valves 28 and the amount of the air by the size and number of the discharge nozzles and the number of rings to which the compressed air is admitted. V

F or slow moving trains, such as freight trains, it will possibly be only necessary to use one of the ring, but for faster, such as passenger trains, all the rings will be in use. They are directly controlled by the throttle valves in the tower and the manipulation of these is left to the discretion of the attendant.

What I claim as my invention is 1. A method or" ventilating train tunnels which consists in maintaining a current of air flowing in the direction of the moving train at a velocity greater than the train.

A method of ventilating train tunnels which consists in producing a relatively small current of air flowing at high velocity in the direction of the train whereby the entire air content or" the tunnel is moved in the same direction at a velocity greater than the train.

Signed at lVinnipe this 22nd day of June, 1915.

ARTHUR CRISFIELD DENNIS.

In the presence of- G. S. ROXBURGH, S. Srnvnn'r.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

